Liquid crystal device and display device

ABSTRACT

According to one embodiment, a liquid crystal device includes a plurality of first light-shielding members arranged at a first pitch, a first organic insulating film covering the first light-shielding members, a plurality of second light-shielding members overlapping the first light-shielding members, a second organic insulating film covering the second light-shielding members, a plurality of third light-shielding members overlapping the second light-shielding members, a third organic insulating film covering the third light-shielding members, and a plurality of first electrodes arranged at a second pitch that is smaller than the first pitch.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.17/940,087, filed Sep. 8, 2022, which is based upon and claims thebenefit of priority from Japanese Patent Application No. 2021-146250,filed Sep. 8, 2021, the entire contents of each are incorporated hereinby reference.

FIELD Embodiments described herein relate generally to a liquid crystaldevice and a display device. BACKGROUND

In recent years, a variety of optical elements which adhere to thedisplay surface of a liquid crystal panel to control a viewing anglehave been proposed.

The optical elements include, for example, a louver layer that limitsthe transmission angle of light. The louver layer is formed by stackinga light-transmitting layer and a light-shielding layer alternately. Thebonding surface between the light-transmitting layer and thelight-shielding layer is inclined at a predetermined angle with respectto the thickness direction of the louver layer.

If the above-described optical elements are externally applied to adevice, the overall thickness of the device increases.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view showing a display device DSPaccording to an embodiment.

FIG. 2 is a diagram showing an example of an equivalent circuit of adisplay panel PNL of the display device DSP shown in FIG. 1 .

FIG. 3 is a sectional view showing an example of a configuration of thedisplay panel PNL shown in FIG. 1 .

FIG. 4 is a sectional view showing an example of a structure of a liquidcrystal device 100 of the display device DSP shown in FIG. 1 .

FIG. 5 is a sectional view showing an example of a configuration of aliquid crystal lens portion 4 of the liquid crystal device 100 shown inFIG. 4 .

FIG. 6 is a schematic diagram showing an OFF-state liquid crystal device100 including a liquid crystal layer LC1 in which no electric field isformed.

FIG. 7 is a schematic diagram showing an ON-state liquid crystal device100 including a liquid crystal layer LC1 in which an electric field isformed.

FIG. 8 is a plan view showing a first electrode E1 and a light-shieldinglayer B1.

FIG. 9 is a plan view showing a light-shielding layer 21 and thelight-shielding layer B1 of the display panel PNL.

FIG. 10 is a plan view showing the first electrode E1 and anotherlight-shielding layer B1.

FIG. 11 is a sectional view showing an example of each oflight-shielding members constituting a louver portion 3.

FIG. 12 is a sectional view showing another example of each of thelight-shielding members constituting the louver portion 3.

FIG. 13 is a sectional view showing still another example of each of thelight-shielding members constituting the louver portion 3.

FIG. 14 is a diagram illustrating the aperture ratio of the louverportion 3.

FIG. 15 is a diagram illustrating the thickness “c” of the louverportion.

DETAILED DESCRIPTION

In general, according to one embodiment, a liquid crystal deviceincludes, a first transparent substrate, a plurality of firstlight-shielding members each formed in a strip shape and arranged at afirst pitch on an inner surface of the first transparent substrate, afirst organic insulating film which is transparent and covers the firstlight-shielding members, a plurality of second light-shielding memberswhich overlap the first light-shielding members, respectively and eachof which is formed in a strip shape parallel to the firstlight-shielding members, a second organic insulating film which istransparent and covers the second light-shielding members, a pluralityof third light-shielding members which overlap the secondlight-shielding members, respectively and each of which is formed in astrip shape parallel to the second light-shielding members, a thirdorganic insulating film which is transparent and covers the thirdlight-shielding members, an overcoat layer disposed above the thirdorganic insulating film, a plurality of first electrodes each formed ina strip shape and arranged on the overcoat layer at a second pitch thatis smaller than the first pitch, a first alignment film which covers thefirst electrodes, a second transparent substrate, a second electrodedisposed on an inner surface of the second transparent substrate andopposed to the first electrodes, a second alignment film which coversthe second electrode, and a liquid crystal layer disposed between thefirst alignment film and the second alignment film.

According to another embodiment, a display device includes anillumination device, a display panel including a plurality of pixelsarranged in a matrix, and a liquid crystal device disposed between theillumination device and the display panel. The liquid crystal deviceincludes a first transparent substrate, a louver portion located on thefirst transparent substrate, an overcoat layer which covers the louverportion, a liquid crystal lens portion located on the overcoat layer,and a second transparent substrate located on the liquid crystal lensportion. The louver portion is disposed between the illumination deviceand the liquid crystal lens portion.

Embodiments will be described hereinafter with reference to theaccompanying drawings.

The disclosure is merely an example, and proper changes within thespirit of the invention, which are easily conceivable by a skilledperson, are included in the scope of the invention as a matter ofcourse. In addition, in some cases, in order to make the descriptionclearer, the widths, thicknesses, shapes, etc., of the respective partsare schematically illustrated in the drawings, compared to the actualmodes. However, the schematic illustration is merely an example, andadds no restrictions to the interpretation of the invention. Besides, inthe specification and drawings, the same or similar elements as or tothose described in connection with preceding drawings or thoseexhibiting similar functions are denoted by like reference numerals, anda detailed description thereof is omitted unless otherwise necessary.

Note that in order for the descriptions to be easily understandable, thedrawings are illustrated with an X axis, a Y axis and a Z axis which arenormal to each other. A direction along the X axis is referred to as anX direction or a first direction, a direction along the Y axis isreferred to as a Y direction or a second direction, and a directionalong the Z axis is referred to as a Z direction or a third direction. Aplane defined by the X axis and the Y axis is referred to as an X-Yplane, and viewing towards the X-Y plane is referred to as a planarview.

FIG. 1 is an exploded perspective view showing a display device DSPaccording to an embodiment.

The display device DSP includes an illumination device IL, a liquidcrystal device 100, a display panel PNL, an optical sheet OS andpolarizers PL1 and PL2.

The illumination device IL is configured to emit illumination lighttoward the display panel PNL. The illumination light is unpolarizedlight, but may be linearly polarized light, for example.

The optical sheet OS is disposed between the illumination device IL andthe liquid crystal device 100 in a third direction Z. The optical sheetOS is, for example, a reflective polarized sheet, and is configured toreflect s-polarized light of the illumination light and transmitp-polarized light thereof. The liquid crystal device 100 is disposedbetween the optical sheet OS and the polarizer PL1 in the thirddirection Z. The liquid crystal device 100 holds a liquid crystal layerbetween a first substrate S1 and a second substrate S2. The liquidcrystal device 100 includes an effective area AA to control the emissiondirection of incident light (illumination light).

The display panel PNL is disposed between the polarizers PL1 and PL2 inthe third direction Z. The display panel PNL is, for example, a liquidcrystal panel in which a liquid crystal layer is held between pairedsubstrates SUB1 and SUB2, but may be another display panel as an objectto be illuminated by the illumination device IL. The display panel PNLincludes a display area DA to display an image. The display area DAoverlaps the effective area AA in the third direction Z.

The display panel PNL and the liquid crystal device 100 will bedescribed in detail later.

FIG. 2 is a diagram showing an example of an equivalent circuit of thedisplay panel PNL shown in FIG. 1 .

The display panel PNL includes a plurality of pixels PX, a plurality ofscanning lines G and a plurality of signal lines S in the display areaDA. The scanning lines G and signal lines S intersect each other. As oneexample, the scanning lines G extend in a first direction X shown inFIG. 1 , and the signal lines S extend in a second direction Y.

The display panel PNL also includes a first driver DR1 and a seconddriver DR2 outside the display area DA. The scanning lines G areelectrically connected to the first driver DR1. The signal lines S areelectrically connected to the second driver DR2. The first and seconddrivers DR1 and DR2 are controlled by a controller.

The pixels PX shown in FIG. 2 are referred to as sub-pixels, colorpixels, and the like, and correspond to, for example, red pixels fordisplaying red, green pixels for displaying green, blue pixels fordisplaying blue, white pixels for displaying white, and the like. Thesepixels PX are separated by, for example, two adjacent scanning lines Gand two adjacent signal lines S.

Each of the pixels PX includes a switching element SW, a pixel electrodePE and a common electrode CE opposed to the pixel electrode PE. Theswitching element SW is electrically connected to the scanning line Gand signal line S. The pixel electrode PE is electrically connected tothe switching element SW. That is, the pixel electrode PE iselectrically connected to the signal line S via the switching elementSW. The common electrode CE is formed over the pixels PX. A commonpotential is applied to the common electrode CE.

The first driver DR1 supplies a scanning signal to each of the scanninglines G. The second driver DR2 supplies a video signal to each of thesignal lines S. In the switching element SW electrically connected tothe scanning line G to which a scanning signal is supplied, the signalline S and the pixel electrode PE are conducted, and a voltagecorresponding to the video signal supplied to the signal line S isapplied to the pixel electrode PE. The liquid crystal layer LC is drivenby an electric field generated between the pixel electrode PE and thecommon electrode CE.

FIG. 3 is a sectional view showing an example of a configuration of thedisplay panel PNL shown in FIG. 1 .

The display panel PNL includes a substrate SUB1, a substrate SUB2 and aliquid crystal layer LC. Here is a description of a display panel PNLadapted to a display mode using a lateral electric field along the mainsurface of substrate, but the display panel PNL is not limited to theconfiguration adapted to the display mode. The display panel PNL hasonly to be configured to correspond to any of a display mode using alongitudinal electric field along the normal of the main surface, adisplay mode using an inclined electric field angled with respect to themain surface, and a display mode using an appropriate combination of thelateral electric field, longitudinal electric field and inclinedelectric field. The main surface is parallel to the X-Y plane.

The substrate SUB1 includes a transparent substrate 10, insulatinglayers 11 and 12 and an alignment film 13 in addition to the switchingelement SW, pixel electrode PE and common electrode CE. The substrateSUB1 also includes the scanning lines G, signal lines S, first driverDR1, second driver DR2 and the like shown in FIG. 1 . The transparentsubstrate 10 has an inner surface 10A opposed to the liquid crystallayer LC and an outer surface 10B that is the opposite side of the innersurface 10A. The polarizer PL1 adheres to the outer surface 10B.

The switching element SW is disposed on the inner surface 10A andcovered with the insulating layer 11. In the example shown in FIG. 3 ,for convenience of description, the switching element SW is simplifiedand the scanning lines G or the signal lines S are not shown. Inpractice, the insulating layer 11 includes a plurality of insulatinglayers, and the switching element SW includes semiconductor layers andvarious electrodes each formed between adjacent insulating layers.

The common electrode CE is disposed over the pixels PX on the insulatinglayer 11 and covered with the insulating layer 12. The pixel electrodePE of each of the pixels PX is disposed on the insulating layer 12 andopposed to the common electrode CE with the insulating layer 12therebetween. The pixel electrode PE is electrically connected to theswitching element SW through an opening OP of the common electrode CEand a contact hole CH that penetrates the insulating layers 11 and 12.The alignment film 13 covers the pixel electrode PE and the insulatinglayer 12 and is in contact with the liquid crystal layer LC.

The substrate SUB2 includes a transparent substrate 20, light-shieldinglayers 21, a color filter layer 22, an overcoat layer 23 and analignment film 24. The transparent substrate 20 has an inner surfaceopposed to the liquid crystal layer LC and an outer surface 20B that isthe opposite side of the inner surface 20A. The polarizer PL2 adheres tothe outer surface 20B.

The light-shielding layers 21 are formed on the inner surface 20A andlocated on the boundary of adjacent pixels PX. As will be describedlater, the light-shielding layers 21 are formed in a lattice shape andoverlap the scanning and signal lines G and S to partition the pixelsPX. The color filter layer 22 includes a red-color filter 22R, agreen-color filter 22-G and a blue-color filter 22B. The overcoat layer23 covers the color filter layer 22. The alignment film 24 covers theovercoat layer 23 and is in contact with the liquid crystal layer LC.

The transparent substrates 10 and 20 are insulating substrates such as aglass substrate and a resin substrate. The pixel electrode PE and thecommon electrode CE are transparent electrodes formed of a transparentconductive material such as indium tin oxide (ITO) and indium zinc oxide(IZO).

FIG. 4 is a sectional view showing an example of a configuration of theliquid crystal device 100 shown in FIG. 1 . Specifically, FIG. 4 shows asectional configuration of part of the effective area AA.

The liquid crystal device 100 includes a first substrate Sl, a secondsubstrate S2 and a liquid crystal layer LC1.

The liquid crystal device 100 includes a louver portion 3 which isdisposed between paired transparent substrates 1 and 2 to regulate theemission direction of incident light (illumination light) and collimatethe incident light, and a liquid crystal lens portion 4 which adjuststhe degree of divergence of the collimated incident light. The louverportion 3 is located between the illumination device IL indicated by adotted line and the liquid crystal lens portion 4. In the example shownin FIG. 4 , the louver portion 3 is built in the first substrate Sl. Theliquid crystal device 100 is configured to control the emissiondirection of incident light (illumination light) in the effective regionAA by the combination of the louver portion 3 and the liquid crystallens portion 4. The following is a description of a configuration ofeach component of the liquid crystal device 100.

The first substrate S1 includes a first transparent substrate 1, aplurality of light-shielding layers B1 to B5, a plurality of organicinsulating films I1 to I4, an overcoat layer OC, a plurality of firstelectrodes E1 and a first alignment film AL1. The louver portion 3 isconfigured by the light-shielding layers B1 to B5. In the example shownin FIG. 4 , the louver portion 3 is configured by five light-shieldinglayers B1 to B5, but may be configured by two or more light-shieldinglayers arranged in the third direction Z.

The first transparent substrate 1 has an inner surface 1A opposed to theliquid crystal layer LC1 and an outer surface 1B that is the oppositeside of the inner surface 1A. The outer surface 1B is opposed to theoptical sheet OS shown in FIG. 1 .

The light-shielding layer B1 includes a plurality of light-shieldingmembers B11 and B12 disposed on the inner surface 1A of the firsttransparent substrate 1.

The light-shielding members B11 and B12 are arranged at a first pitch P1in the first direction X. The light-shielding members B11 and B12 areeach formed in a strip shape extending in a direction crossing the firstdirection X and are parallel to each other as will be described later.

The organic insulating film I1 covers the light-shielding members B11and B12 and also covers the first transparent substrate 1.

The light-shielding layer B2 includes a plurality of light-shieldingmembers B21 and B22 disposed on the organic insulating film I1. Thelight-shielding members B21 and B22 are in contact with the organicinsulating film I1 and are arranged at a first pitch P1 in the firstdirection X. The light-shielding members B21 and B22 overlap thelight-shielding members B11 and B12, respectively, and are each formedin a strip shape parallel to the light-shielding members B11 and B12.That is, the light-shielding member B21 is located immediately above thelight-shielding member B11 with the organic insulating film I1therebetween, and the light-shielding member B22 is located immediatelyabove the light-shielding member B12 with the organic insulating film I1therebetween.

The organic insulating film I2 covers the light-shielding members B21and B22 and also covers the organic insulating film I1.

The light-shielding layer B3 includes a plurality of light-shieldingmembers B31 and B32 disposed on the organic insulating film I2. Thelight-shielding members B31 and B32 are in contact with the organicinsulating film I2 and are arranged at a first pitch P1 in the firstdirection X. The light-shielding members B31 and B32 overlap thelight-shielding members B21 and B22, respectively, and are each formedin a strip shape parallel to the light-shielding members B21 and B22.That is, the light-shielding member B31 is located immediately above thelight-shielding member B21 with the organic insulating film I2therebetween, and the light-shielding member B32 is located immediatelyabove the light-shielding member B22 with the organic insulating film I2therebetween. The organic insulating film I3 covers the light-shieldingmembers B31 and B32 and also covers the organic insulating film I2.

The light-shielding layer B4 includes a plurality of light-shieldingmembers B41 and B42 disposed on the organic insulating film I3. Thelight-shielding members B41 and B42 are in contact with the organicinsulating film I3 and are arranged at a first pitch P1 in the firstdirection X. The light-shielding members B41 and B42 overlap thelight-shielding members B31 and B32, respectively, and are each formedin a strip shape parallel to the light-shielding members B31 and B32.That is, the light-shielding member B41 is located immediately above thelight-shielding member B31 with the organic insulating film I3therebetween, and the light-shielding member B42 is located immediatelyabove the light-shielding member B32 with the organic insulating film I3therebetween.

The organic insulating film I4 covers the light-shielding members B41and B42 and also covers the organic insulating film I3.

The light-shielding layer B5 includes a plurality of light-shieldingmembers B51 and B52 disposed on the organic insulating film I4. Thelight-shielding members B51 and B52 are in contact with the organicinsulating film I4 and are arranged at a first pitch P1 in the firstdirection X. The light-shielding members B51 and B52 overlap thelight-shielding members B41 and B42, respectively, and are each formedin a strip shape parallel to the light-shielding members B41 and B42.That is, the light-shielding member B51 is located immediately above thelight-shielding member B41 with the organic insulating film I4therebetween, and the light-shielding member B52 is located immediatelyabove the light-shielding member B42 with the organic insulating film I4therebetween.

The overcoat layer OC covers the light-shielding members B51 and B52 andalso covers the organic insulating film I4. That is, the overcoat layerOC covers the louver portion 3.

The first electrodes E1 are disposed on the overcoat layer OC. The firstelectrodes E1 are also arranged at a second pitch P2 in the firstdirection X. The second pitch P2 is smaller than the first pitch P1.

As will be described later, the first electrodes E1 are each formed in astrip shape extending in a direction crossing the first direction X andare parallel to each other.

The first alignment film AL1 covers the first electrodes E1 and theovercoat layer OC. The first alignment film AL1 is also in contact withthe liquid crystal layer LC1.

In the first substrate S1 described above, for example, each of thelight-shielding members B11 and B12 corresponds to a firstlight-shielding member, each of the light-shielding members B21 and B22corresponds to a second light-shielding member, each of thelight-shielding members B31 and B32 corresponds to a thirdlight-shielding member, the organic insulating film I1 corresponds to afirst organic insulating film, the organic insulating film I2corresponds to a second organic insulating film and the organicinsulating film I3 corresponds to a third organic insulating film.

The second substrate S2 includes a second transparent substrate 2, asecond electrode E2 and a second alignment film AL2. The secondtransparent substrate 2 has an inner surface 2A opposed to the liquidcrystal layer LC1 and an outer surface 2B that is the opposite side ofthe inner surface 2A. The outer surface 2B is opposed to the polarizerPL1 shown in FIG. 1 .

The second electrode E2 is disposed on the inner surface 2A of thesecond transparent substrate 2. The second alignment film AL2 covers thesecond electrode E2 and is in contact with the liquid crystal layer LC1.

A spacer SP is formed, for example, in a columnar shape and disposedbetween the first substrate Sl and the second substrate S2 to hold a gapof, for example, pm or more.

The liquid crystal layer LC1 is formed between the first alignment filmAL1 and the second alignment film AL2. The thickness TLC of the liquidcrystal layer LC1 along the third direction Z is 10 μm or more.

The liquid crystal lens portion 4 is configured by the first electrodesE1, the liquid crystal layer LC1 and the second electrode E2.

The first transparent substrate 1 and the second transparent substrate 2are insulating substrates such as a glass substrate and a resinsubstrate.

The light-shielding members B11, B12, B21, B22, B31, B32, B41, B42, B51and B52 are formed of a resin material containing, for example, a blackpigment, but may be formed of a metal material.

The organic insulating films I1, I2, I3 and I4 and the overcoat layer OCare formed of a transparent resin material such as an acrylic resin.

The first and second electrodes E1 and E2 are transparent electrodesformed of a transparent conductive material such as indium tin oxide(ITO) and indium zinc oxide (IZO). The first and second alignment filmsAL1 and AL2 are horizontal alignment films having an alignmentregulating force that is substantially parallel to the X-Y plane.

Here is a description of a case where each of the light-shieldingmembers B11, B21, B31, B41 and B51 is formed of a resin material.

Each of the light-shielding members B11, B21, B31, B41 and B51 has asubstantially rectangular section.

The light-shielding members B11, B21, B31, B41 and B51 have the samewidth “a” along the first direction X, and the width “a” is, forexample, 5.5 μm. The distance “b” between adjacent light-shieldingmembers arranged in the first direction X is larger than the width “a”,and is, for example, 14.5 μm. The first pitch P1 is, for example, 20 μm.

The light-shielding members B11, B21, B31, B41 and B51 have thicknessesT11, T12, T13, T14 and T15, respectively along the third direction Z.These thicknesses are the same and are each preferably 1 μm or more, forexample, 2 μm.

The greater the thickness of each of the light-shielding members, thesmaller the number of light-shielding layers to configure the louverportion 3. On the other hand, if the thickness of each of thelight-shielding members is small, a large number of light-shieldinglayers are required to collimate transmitted light. The organicinsulating films I1, I2, I3 and I4 have thicknesses T1, T2, T3 and T4,respectively along the third direction Z. These thicknesses are the sameand are each 8.5 μm, for example.

The overcoat layer OC is thinner than the organic insulating film I1.That is, the thickness T5 of the overcoat layer OC along the thirddirection Z is smaller than the thickness T1, and is 2.5 μm, forexample.

The liquid crystal layer LC1 is thicker than the organic insulating filmI1. That is, the thickness TLC of the liquid crystal layer LC1 isgreater than the thickness T1, and is 10 μm, for example. The overcoatlayer OC is thus thinner than the liquid crystal layer LC1.

FIG. 5 is a sectional view showing an example of a configuration of theliquid crystal lens portion 4 shown in FIG. 4 . In FIG. 5 , the louverportion 3 in the first substrate S1 is simplified, and no spacer isshown. The liquid crystal layer LC1 is sealed by a sealant SE.

The first electrodes E1 include a plurality of first strip electrodesE11 and a plurality of second strip electrodes E12. The first and secondstrip electrodes E11 and El2 are alternately arranged at the secondpitch P2 in the first direction X.

The first strip electrodes E11 are electrically connected to each otherand are configured to be applied with a first voltage via a feeder lineFL1.

The second strip electrodes El2 are electrically connected to each otherand are configured to be applied with a second voltage via a feeder lineFL2. The first voltage is different from the second voltage.Accordingly, a potential difference is formed between adjacent first andsecond strip electrodes E11 and E12, with the result that an electricfield can be formed in the liquid crystal layer LC1.

A feeding terminal PT1 is electrically connected to a feeder line FL3and pulled outside the sealant SE.

The feeding terminal PT1 is exposed from the first alignment film AL1.

A feeding terminal PT2 is electrically connected to the second electrodeE2 and pulled outside the sealant SE. The feeding terminal PT2 islocated directly above the feeding terminal PT1. The feeding terminalPT2 is exposed from the second alignment film AL2.

A conductive member CD is disposed between the feeding terminals PT1 andPT2 to electrically connect them to each other.

The optical function of the liquid crystal device 100 will be describedbelow with reference to FIGS. 6 and 7. Note that FIGS. 6 and 7 show onlythe configurations necessary for descriptions.

FIG. 6 is a schematic diagram showing the liquid crystal device 100 inan OFF state in which no electric field is formed in the liquid crystallayer LC1.

Of the illumination light emitted from the illumination device IL,p-polarized light POLI transmitted through the optical sheet OS entersthe first substrate S1 of the liquid crystal device 100. Then, thep-polarized light POLI is collimated in the louver portion 3 of thefirst substrate S1. The collimated p-polarized light POLI enters theliquid crystal lens portion 4.

In the liquid crystal layer LC1 in an OFF state, the liquid crystalmolecules LM1 are initially aligned. In this OFF state, the liquidcrystal layer LC1 has a substantially uniform refractive-indexdistribution. Thus, the p-polarized light POLI, which is light incidentupon the liquid crystal lens portion 4, is hardly refracted (ordiverged) but transmitted through the liquid crystal layer LC1.

If, therefore, the liquid crystal lens portion 4 of the liquid crystaldevice 100 is in an OFF state, illumination light with a relativelysmall degree of divergence can be formed, and an image can be displayedin a narrow viewing angle mode by light transmitted through the displaypanel PNL.

FIG. 7 is a schematic diagram showing the liquid crystal device 100 inan ON state in which an electric field is formed in the liquid crystallayer LC1.

If the liquid crystal layer LC1 has, for example, positive dielectricconstant anisotropy, the liquid crystal molecules LM1 are aligned sothat their major axes follow the electric field in the ON state where anelectric field is formed in the liquid crystal layer LC1. In the liquidcrystal layer LC1, for example, an electric field is formed inaccordance with a potential difference between adjacent first electrodesE1 and a potential difference between each of the first electrodes E1and the second electrode E2. When the electric field acts on the liquidcrystal layer LC1, an area in which the liquid crystal molecules LM1rise substantially perpendicularly to the substrate, an area in whichthe liquid crystal molecules LM1 are maintained in the initial alignmentstate, an area in which the liquid crystal molecules LM1 rise obliquelyto the substrate, and the like are formed in the liquid crystal layerLC1.

The liquid crystal molecules LM1 have refractive anisotropy An. Thus,the ON-state liquid crystal layer LC1 has a refractive indexdistribution or a retardation distribution which corresponds to thealignment state of the liquid crystal molecules LM1.

The retardation is expressed by Δn·d, where d is the thickness of theliquid crystal layer LC1 (or a gap between the first and secondsubstrates S1 and S2).

In the above-described ON state, when the collimated p-polarized lightPOLI is transmitted through the liquid crystal layer LC1, it is divergedunder the influence of the refractive index distribution in the liquidcrystal layer LC1. The degree of divergence of the transmitted light canbe controlled by a voltage to be applied to the liquid crystal layerLC1.

Therefore, when the liquid crystal lens portion 4 of the liquid crystaldevice 100 is turned on, illumination light having a relatively highdegree of divergence can be formed, and an image can be displayed in awide viewing angle mode by light transmitted through the display panelPNL.

As described above, the liquid crystal device 100 including the louverportion 3 and the liquid crystal lens portion 4 makes it possible tocontrol the emission direction of illumination light emitted from theillumination device IL.

The liquid crystal device 100 also makes it possible to make the entiredevice thinner than a case where an optical element having a louverportion on a substrate is required, in addition to a liquid crystalelement having a liquid crystal lens portion between paired substrates.

FIG. 8 is a plan view showing one of the first electrodes E1 and thelight-shielding layer B1. The light-shielding layer B1 is one of thelight-shielding layers constituting the louver portion, and the otherlight-shielding layers B2 to B5 overlap immediately above thelight-shielding layer B1.

As described above, the first electrodes E1 include first stripelectrodes E11 and second strip electrodes E12 arranged alternately inthe first direction X. The first and second strip electrodes E11 and E12extend in the second direction Y.

The light-shielding layer B1 includes light-shielding members B11 to B15arranged in order in the first direction X. The light-shielding membersB11 to B15 are parallel to each other and extend in a direction otherthan the second direction Y. That is, the light-shielding members B11 toB15 intersect the first electrodes E1 in planar view. In other words,the light-shielding members B11 to B15 extend in a direction other thanthe extending direction of the first and second strip electrodes E11 andE12.

Paying attention to the light-shielding member B11, for example, thereference orientation indicated by the dotted line in FIG. 8 is parallelto the second direction Y, and the light-shielding member B11 extends ina direction rotated by angle θ clockwise from the reference orientation.The angle θ is an acute angle and is 4°, for example.

In configuring the liquid crystal lens portion 4, the voltage applied tothe liquid crystal layer LC1 can be more reduced as the second pitch P2becomes smaller, and the thickness TLC of the liquid crystal layer LC1can be decreased. It is therefore desirable that the second pitch P2 beset to a minimum pitch at which the first electrodes E1 can be machined.

The first pitch P1 is set from the viewpoint of required louverperformance, aperture ratio, machinability of the light-shieldingmembers, and the like. An example of setting the first pitch P1 will bedescribed later.

FIG. 9 is a plan view showing one of the light-shielding layers 21 andlight-shielding layer B1 of the display panel PNL. The light-shieldinglayer B1 is one of the light-shielding layers constituting the louverportion, which is shown by a dotted line.

The light-shielding layer 21 has first portions 21X extending in thefirst direction X and second portions 21Y extending in the seconddirection Y, and is formed in a lattice shape. For example, the firstportions 21X overlap the scanning lines G, and the second portions 21Yoverlap the signal lines S.

Square apertures AP are formed in the light-shielding layer 21 andoverlap the pixels PX or pixel electrodes PE shown in FIG. 3 . As oneexample, the apertures AP are each formed in a rectangular shapeextending in the second direction Y, but the shape is not limited to therectangle.

The apertures AP are arranged in a matrix in the first and seconddirections X and Y. For example, the apertures AP are arranged at apixel pitch P11 in the first direction X.

The light-shielding members B11 to B15 of the light-shielding layer B1intersect the first and second portions 21X and 21Y of thelight-shielding layer 21. The first pitch P1 of the light-shieldingmembers B11 to B15 is smaller than the pixel pitch P11. The pixel pitchP11 is, for example, 20 μm to 100 μm.

As described above, in the display device DSP, when the liquid crystaldevice 100 and the display panel PNL overlap each other, thelight-shielding layers B1 and 21 intersect each other, and the pixelpitch P11 and the first pitch P1 are different from each other. Thus,undesired moire can be suppressed and display quality can be preventedfrom lowering.

FIG. 10 is a plan view showing one of the first electrodes E1 andanother light-shielding layer B1. The light-shielding layer B1 is one ofthe light-shielding layers constituting the louver portion.

The light-shielding layer B1 shown in FIG. 10 differs from thelight-shielding layer B1 shown in FIG. 8 in that the light-shieldingmembers are formed in a zigzag shape.

The light-shielding members B11 to B15 are parallel to each other andextend in a direction other than the second direction Y. Thelight-shielding members B11 to B15 intersect the first electrodes E1 inplanar view.

Paying attention to the light-shielding member B11, it has a pluralityof first portions BA and a plurality of second portions BB. The firstportions BA and the second portions BB extend in mutually differentdirections and are alternately arranged along the second direction Y.The reference orientation indicated by the dotted line in FIG. 10 isparallel to the second direction Y. The first portions BA extend in adirection rotated by angle θA clockwise from the reference orientation,and the second portions BB extend in a direction rotated by angle θBcounterclockwise from the reference orientation. The angles OA and OBare equal, and both are acute angles and are 4°, for example.

The larger a pitch P3 along the second direction Y between adjacentfirst and second portions BA and BB, the lower the visibility of moire.As one example, the pitch P3 is 100 μm or more.

FIGS. 11 and 12 are sectional views each showing another example of eachof the light-shielding members constituting the louver portion 3. Theexamples shown in FIGS. 11 and 12 differ from the example shown in FIG.4 in that each of the light-shielding members B11, B21, B31, B41 and B51has a trapezoidal section.

In the example shown in FIG. 11 , each of the light-shielding membersB11, B21, B31, B41 and B51 has a forward-tapered section in which thewidth “a” of each of the members decreases upward along the thirddirection Z.

In the example shown in FIG. 12 , each of the light-shielding membersB11, B21, B31, B41 and B51 has a reverse-tapered section in which thewidth “a” of each of the members increases upward along the thirddirection Z. The light-shielding members B11, B21, B31, B41 and B51 areeach formed of a resin material, for example, but the light-shieldingmember B11 may be formed of a metal material.

In addition, some of the light-shielding members B11, B21, B31, B41 andB51 may have a forward-tapered section and the other light-shieldingmembers may have a reverse-tapered section.

FIG. 13 is a sectional view showing another example of each of thelight-shielding members constituting the louver portion 3. The exampleshown in FIG. 13 differs from the example shown in FIG. 4 in that atleast one of the light-shielding members B11, B21, B31, B41 and B51 hasa constricted section in its middle. In the example shown in FIG. 13 ,the light-shielding member B11 is formed of a metal material (forexample, molybdenum tungsten alloy), and the light-shielding membersB21, B31, B41 and B51 are each formed of a resin material. Thethicknesses T21, T31, T41 and T51 of the light-shielding members B21,B31, B41 and B51 are equal and, for example, 2 μm. The light-shieldingmember B11 is thinner than each of the light-shielding members B21, B31,B41 and B51. That is, the thickness T11 is smaller than the thicknessT21 and is, for example, less than 1 μm.

Focusing on the light-shielding member B21, it has a lower portion BL2,an upper portion BU2 and an intermediate portion BM2. The lower portionBL2 is a portion opposed to the first transparent substrate 1 or theorganic insulating film I1. The upper portion BU2 is a portion opposedto the liquid crystal layer LC1 shown in FIG. 4 . The intermediateportion BM2 is a portion located between the lower portion BL2 and theupper portion BU2.

The width aL2 of the lower portion BL2 is equal to the width aU2 of theupper portion BU2. Note that the width aL2 may be smaller or larger thanthe width aU2.

The width aM2 of the intermediate portion BM2 is smaller than each ofthe widths aL2 and aU2.

Comparing the shapes of the light-shielding members B21, B31, B41 andB51, the width of the intermediate portion tends to increase withdistance from the light-shielding member B11.

Comparing, for example, the light-shielding members B21 and B31, thewidth aM2 of the intermediate portion BM2 of the light-shielding memberB21 is smaller than the width aM3 of the intermediate portion BM3 of thelight-shielding member B31.

Note that the width in this description corresponds to a length alongthe first direction X.

FIG. 14 is a diagram illustrating the aperture ratio of the louverportion 3.

Each of the light-shielding members B21, B31, B41 and B51 is locateddirectly above the light-shielding member B11, and each of thelight-shielding members B22, B32, B42 and B52 is located directly abovethe light-shielding member B12.

The aperture ratio of the louver portion 3 can be defined as (b/(a+b)),where “a” is the width of the light-shielding member B11 and “b” is theinterval between the light-shielding members B11 and B12. The width “a”is desirably 3 pm or more, the interval “b” is desirably 10 μm or more,and the aperture ratio is desirably 60% or more.

FIG. 15 is a diagram illustrating the thickness “c” of the louverportion 3.

It is assumed here that the louver portion 3 is configured by fivelight-shielding layers B1 to B5, and the length from the bottom surfaceof the lowermost light-shielding layer B1 to the top surface of theuppermost light-shielding layer B5 along the third direction Z isdefined as the thickness “c” of the louver portion 3.

An optical path R1 which passes nearby the light-shielding member B11between the light-shielding members B11 and B12 and reaches thelight-shielding member B52, and an optical path R2 through which lightis emitted into the air from the louver portion 3 are indicated by thedotted lines in FIG. 15 .

When the refractive index of the organic insulating film covering eachof the light-shielding layers B1 to B5 is n1, the refractive index ofair is n2, the angle of the optical path R1 with respect to the normal Nof the first transparent substrate 1 is θ1, and the angle of the opticalpath R2 with respect to the normal N is θ2, a relationship among thesedefinitions is represented by an equation (1) in FIG. 15 .

In the equation (1), sinθ1 is expressed as an equation (2) in FIG. 15 .Substituting the equation (2) into the equation (1) and solving for “c”,the relationship of an equation (3) holds. That is, the thickness “c” ofthe louver portion 3 is set based on the equation (3). The angle θ2 inthe equation (3) is the lower limit value of the angle formed between anoptical path of light to be shielded and the normal N.

Next is a description of an interval “c′” along the third direction Z ofthe light-shielding layers B1 to B5. Among the optical paths parallel tothe optical path R1, for example, an optical path R3 which passes nearbythe light-shielding member B42 and reaches the light-shielding layer B52between the light-shielding members B42 and B52 is indicated by a dottedline in FIG. 15 . In order to block the light beam passing through theoptical path R3 by the light-shielding member B42 or B52, it is requiredthat the interval “c′” satisfies the relationship of the equation (4) inFIG. 15 .

The number of light-shielding layers constituting the louver portion 3is determined based on the intervals “c′” and “b”.

According to the foregoing embodiment, a liquid crystal device forcontrolling a viewing angle, which can be thinned, and a display deviceincluding the liquid crystal device, can be provided.

Based on the liquid crystal device which has been described in theabove-described embodiments, a person having ordinary skill in the artmay achieve a liquid crystal device with an arbitral design change;however, as long as they fall within the scope and spirit of the presentinvention, such a liquid crystal device shall be encompassed by thescope of the present invention.

A skilled person would conceive various changes and modifications of thepresent invention within the scope of the technical concept of theinvention, and naturally, such changes and modifications are encompassedby the scope of the present invention. For example, if a skilled personadds/deletes/alters a structural element or design to/from/in theabove-described embodiments, or adds/deletes/alters a step or acondition to/from/in the above-described embodiment, as long as theyfall within the scope and spirit of the present invention, suchaddition, deletion, and altercation are encompassed by the scope of thepresent invention.

Furthermore, regarding the present embodiments, any advantage and effectthose will be obvious from the description of the specification orarbitrarily conceived by a skilled person are naturally consideredachievable by the present invention.

What is claimed is:
 1. A display device comprising: an illuminationdevice; a display panel including a plurality of pixels arranged in amatrix; and a liquid crystal device disposed between the illuminationdevice and the display panel, wherein: the liquid crystal deviceincludes: a first transparent substrate; a louver portion located on thefirst transparent substrate; an overcoat layer which covers the louverportion; a liquid crystal lens portion located on the overcoat layer;and a second transparent substrate located on the liquid crystal lensportion; and the louver portion is disposed between the illuminationdevice and the liquid crystal lens portion.
 2. The display device ofclaim 1, wherein: the louver portion includes: a plurality of firstlight-shielding members each formed in a strip shape and arranged on aninner surface of the first transparent substrate at a first pitch in afirst direction; a first organic insulating film which is transparentand covers the first light-shielding members; a plurality of secondlight-shielding members which overlap the first light-shielding members,respectively and each of which is formed in a strip shape parallel tothe first light-shielding members; and a second organic insulating filmwhich is transparent and covers the second light-shielding members; andthe first pitch is smaller than a pixel pitch at which the pixels arearranged along the first direction.
 3. The display device of claim 2,wherein the liquid crystal lens portion includes: a plurality of firstelectrodes each formed in a strip shape and arranged on the overcoatlayer in the first direction at a second pitch that is smaller than thefirst pitch; a first alignment film which covers the first electrodes; asecond electrode disposed on an inner surface of the second transparentsubstrate and opposed to the first electrodes; a second alignment filmwhich covers the second electrode; and a liquid crystal layer disposedbetween the first alignment film and the second alignment film.